Tilting Surface Kneeling Chair

ABSTRACT

A kneeling chair is provided with tilting seat plate and tilting knee plate with rotational tilt of the seat plate enabling the sitting to individual to sit back on a generally horizontal oriented or partially inclined positions of the seat without leaving the chair. The range of tilt is controllable by varied location of the axis of rotation and stops which can be adjusted. The rotation may be dampened by a brake apparatus provided.

CROSS REFERENCE TO RELATED APPLICATION

This Application claims the benefit of prior copending U.S. ProvisionalApplication No. 61/054,390 filed May 19, 2008

BACKGROUND OF THE INVENTION

The invention relates to tilting surfaces for seats and supports onkneeling chairs.

Background of the Invention-Prior Art

A kneeling chair provides two sites of support for the sitting person.The person sits upon an inclined plane with the angle of the legs andtorso (at the hips) held in a more open angle than the typical sittingangle of approximately 90 degrees. The weight of the person is carriedthrough the spine into pelvis ischial bones which normally bear theweight of sitting, however the inclined sitting plate requires that asecond vector of resistance be provided to prevent skidding off of theincline. This second vector site of weight bearing is carried throughthe knees and lower leg which contact a kneel plate which is inclinedtoward the sitting plate.

The knees are flexed somewhat in the manner of kneeling, however theangle of the flexed knees is not usually so acute as the angle neededfor kneeling on the ground.

Another difference from the posture of typical kneeling on the ground,is that the lower leg also contacts the kneel plate along the bonyanterior tibial region of the lower leg.

Since the knee and tibia are elevated above floor level upon the kneelplate, the ankles and feet are relatively freed from any duty of supportand free to hang loosely tucked under the body of the kneeling-sittingindividual.

It is generally believed that the benefit of this partial kneelingposture, with more open hip angle, allows the sitting individual toassume a spinal curvature with more lumbar extension, or lordosis whichtends more toward the spinal curvature of ordinary standing. Typically akneeling chair does not provide a back support and this is founded onthe principle that the sitting individual provides a natural bestalignment of the skeleton using a dynamic balance of the existingmuscle, tendon, and ligamentous stabilizers. Therefore a back support isrendered moot by a configuration which removes the restriction ofsitting on the typical chair, which provides a nearly horizontal sittingplate. Rather than providing a back support which actually limits subtleback motions, a kneeling individual is free to move the back accordingto unconscious choices motivated by comfort and intrinsic muscle tone.

Some would describe the center of balance chosen by the kneeling sitteras being analogous to the unconscious balancing carried out by abicyclist finding the center of gravity on a coasting bike. Theprinciple of freeing the sitter to seek out one's own balance is alsothe theme of those who advocate a simple large ball as ideal for seatedtasks. The so called “sitting ball” or “exercise ball” has also beenreferred to as a “stability ball” which would seem to be a conundrum ifnot for the internal postural stability that seems to be gained by itsdevotees. The sitter upon an exercise ball is free to migrate in minorways from the top center location, as long as the body is braced by feetupon the floor. The directions of migration to relieve the tedium of asingle posture are usually forward and back which may be analogous torocking in a chair, but also some lateral tilting allows a shift to moreor less weight bearing to one hemiregion of the pelvis.

Ordinary chair sitters also seek variance for leg posture as well as forspinal posture. Chair sitters may back away from a task to cross legs,or lean into a task to totally escape a back support for a while.Despite the shifting postures available upon an exercise ball, thesitter tends to keep both feet well planted upon the floor forsufficient stability or sometimes cross the legs below the knee level.The kneeling chair sitter is also able to deploy other variances suchleaning laterally, by shifting to a solitary leg for the knee levelsupport and propping the freed leg at other angles.

Kneeling chairs have at least two frame configurations which are shownas prior art figures in the specifications. Kneeling chairs known to theinventor provide two support plates which are a sitting plate and akneel plate, both of which are fixed in orientation.

The fixed orientation presents a fundamental limit to sitting back inthe manner of an ordinary stool having no back support. In the postureof sitting on a stool both legs would be freed for a while from theincessant duty of at least one knee (and tibia) having to provide acounter resistance to the tendency of upper body to skid down off of theinclined sitting plate. Such a standard stool sitting posture attemptedon a fixed inclined plane becomes quickly uncomfortable.

It is a tenet of the advocates of kneeling chair that the user is freedfrom back support by the self training and freedom of choice residing inthe body and mind of the user and the user is deemed capable ofmaintaining a posture of choice. To the contrary, it is the kneelingchair with fixed inclined surfaces that demands the most incessantdeployment of a rather narrow range of posture (even if that posture hasgood long term attributes and benefits). When the user tires of thatbeneficial posture the user must leave the chair entirely unless thechair is modified to accommodate excursions away from the dictates of afixed chair with fixed angles.

OBJECTS OF THE INVENTION

The invention sets out to provide a kneeling chair with a range ofpositions for its sitting plate and its kneeling plate which are notfixed in relation to the chair frame.

The weight bearing plates provides variance in tilting of both the kneelplate and the sitting plate according to the postures assumed by thesitter and the anatomy of the sitter.

The sitting plate will provide a range from a kneeling incline in a mostforward tilt in kneeling and a somewhat horizontal position for sittingback as upon a stool.

Rather than simply hinging either plate to a frame, the adjustablefeatures are provided with attention to safety in motion includingbraking and limit stops.

Additional features attend to strength and to effective assembly eitherin a factory or in a ready to assemble package carried out by an owner.

Finally attention is directed to spatial features which reduce risk ofpinch injury to hands (of either the user or wandering toddlers) whenthe chair is in use.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is perspective drawing of an X frame kneeling chair with fixedplates demonstrating prior art

FIG. 2. is a perspective drawing of a C frame kneeling chair with fixedplates demonstrating prior art

FIG. 3 is a perspective view of an X frame kneeling chair with tiltingseat shown back in horizontal position and with kneel plate.

FIG. 4. is a closeup perspective of the tilting and braking hardware fora tilting seatplate which is shown tilted to forward incline

FIG. 5 is a rear perspective view of an X frame kneeing chair showingmore detail again with seat plate in forward incline

FIG. 6. is perspective of the frame extension for a C frame kneelingchair to which the disclosed hardware can be mounted

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows a prior art kneeling chair with seatplate 1 and kneelplate2 which are fixed to respective portions of the Xframe member 3 andx_member 4 which are pinned at axle 5. It is common in the prior art forthis to be a ready to assemble furniture which also has a strut 6 whichmay have adjustable length so that the overall sitting height may bevaried according to strut length. Such prior art provides mounting ofthe strut 6 so that small amounts of pivot may occur where the strutjoins member 3 or member 4, which is necessary if length is changed tovary the angle at axle 5. In the only examples known to the inventorhowever, the sitting and kneel plates are not adjustable. In a typical Xframe either plate may be shimmed in its relationship to its connectingmember, as in a common example known and shown providing wedge 7. Thewedge 7 defines a fixed angle of incline different from the surface ofmember 3 and a tapered cut of the upper end of member 3 merges into thatsame angle. It is common for the kneel plate 2 to be fixed to the member4 without any shim. The X frame must follow some dictates of frameheight and length for overall stability communicating to the floor barsunder an average sized sitter, and this angle of the X may not be theideal angle of incline for either plate. Once the X angle is defined itmay serve one plate or the other and the decision to shim one or theother plate (or both plates) in relation to an X member is a matter ofchoosing the best average for a range of human users dimensions. Thearbitrating designers have seen fit to provide fixed seat plates andknee plates.

FIG. 2 shows the prior art of a C frame kneeling chair with seatplate 1and kneel plate 2 fixed to a continuous C frame which has down turnedends at both ends 8 and a broad flat region contacting the floor. In arocker version of the C frame, the floor region is molded to a rockerbottom. The paired C frames are joined both by the fixed plates ofseatplate 1 and kneel plate 2 and by supplemental plates between the Cframes as shown at 9. The angle of the down turned ends 8 is arbitratedin the mold to best fit for average users and the plates are fixed tothe angle provided in the frame, therefore without any need for a wedgemodifier as discussed in the decision task for the X frame described inFIG. 1.

FIG. 3 depicts an x frame kneeling chair with seatplate 1 tilted back toits more or less horizontal position in the manner for sitting back.Both the seatplate 1 and kneelplate 2 are joined to their respective xmembers 3 and 4 by a pivoting axis defined by tube members 24 and 25.Tubular member 24 and 25 are analogous in their service for rotation ofeither plate and may vary in size which influences the available degreesof rotation until impingement upon any frame region or any providedstops. Most of the discussion is directed to the larger tube 24 which ismost visible in this drawing and in the later figures of detailed viewwhich follow, but tube 25 is comparable in the same discussion terms.

FIG. 3 shows an angular modification of X member 3 at its top formounting a frame extension 10 which cantilevers back to provide mountingsurface for stops 11 which are provided as a pair at the backward limitof rotation for seatplate 1 (the pair can be visualized in otherfigures).

The forward tilt of seatplate 1 is variable through a range untilreaching a forward stop 13 which is preferred to be a compressiblematerial joined to an adjustable rod 12 having threaded relationship toa threaded region within x member 3. The threaded region is served by apress fitted threaded insert which need not be shown.

To the extent that locking of the chosen height is needed, it can beprovided by a locking wheel 14 which contains a central threaded regiontraveling on the same threaded rod 12.

It must be noted that stops at 11 and at 13 should be provided withupper regions which are compressible compound such as rubber, molded tothe remaining structure of the body of stop 11 or 13. The height of thestops 11 or 13 and the diameter of the tube member 24 is provisioned toexceed the dimension of a human adult finger as it is common for thehands to be casually dangled downward into areas at risk of pinchinjury. Accordingly the risk of pinch is limited to the cushionedportion of any stop that is provided.

The kneel plate 2 is in a region less prone for pinch injury by a userwho is unlikely to reach toward the feet in a casual manner. It shouldbe noted that the X member 4 is not modified by any plate such as frameextension 10 provided under the seatplate plate 1. This means that thefoundation surface is the plain 180 degree surface of the X memberitself and the range of rotation is limited by the small offset of theaxis of rotation above the X member surface. In the case of the seatplate, the greater than 180 degree angle which is achieved between thesurface of frame extension 10 and x member 3 allows greater angularrotation of seat plate 1. A kneel plate 2 does not require the greaterrange of rotation but this could be provided by analogous modificationof supporting member 4 with an elevating spacer or simply increasing thediameter of tube 25.

Any stops in the kneeling region which are not mandated to prevent pinchinjury may still be mandated also to prevent damage between collision ofparts, which can occur specifically where edge 26 impinges on the uppersurface of x member 4 and also where the under surface of kneel plate 2impinges on the forward edge 27 of x member 4.

If it is chosen to provide the pinch protection with bumper stopsmounted at these surfaces, then the diameter of tube member 25 (which isalso surface mounted to the x member 4) should be increased to define anaxis of rotation which exceeds the height of a stop in any directionaccordingly to allow sufficient angular motion of kneel plate 2 in bothdirections in relation to those elevated stops.

It should be noted that the range of rotation between a paired plate andsupporting member are proportional to the offset of the axis of thetubular axle and this offset can be increased either by enlarging thediameter of the tubular axle or by inserting a bulky shim between theaxle and the plate or the supporting member. to provide a greater degreeof rotation. This description is provided to show that the diameter ofthe tube serves as an offset feature that would otherwise have to beprovided by other elements in the paradigm of hinges (such as offsethinges or hinges provided with interposing matrix of very thick shimplates) all of which would be mounted in a mid region of kneel plate 2.It must be noted that the focus of pivot for either plate 1 or 2 is inthe mid region of the plate and the range of rotation is in twodirections. A leaf hinge if mounted in a mid region would offerdifficult methods for mounting since a leaf hinge must be mounted withits leaves relatively entirely opened and a leaf hinge is madeaccessible by being on the edge of its object during mounting (such as aedge of a door rather than in the door's middle region)

Each plate is aligned to each tube member by straps which can be typicalpipe straps such as are used to surface mount tubular conduit. Eachplate or X member is provided a pair of straps, so that there are twopairs of straps per tube member which are intended to be mountedrelatively far apart to provide the most torsional stability againstdeviation away from the axis which is defined by the tube member. Thestraps, such as 22 to the frame and 23 to the seat plate, are alsolabeled in FIGS. 4 and 5 which has a closer view.

FIG. 4 shows seatplate 1 in a wire frame outline in forward tiltedposition to rest on stop 13. The lock wheel 14 is shown as accessiblenear the front edge of seatplate 1. Fixed strap 22 secures the tubemember 24 to the frame extension 10 and it should be noted that motionis disallowed at this strap by a central screw penetrating through boththe arc of fixed strap 22 and the tube member 24 and which is visiblewhere the label leader for numeral 22 contacts the fixed strap 22. Thismeans that the fixed tube member 24 is enabled to serve as a brakingsurface in relation to the rotating seat to be described later. In thisview the slip straps which secure the tube member 24 to allow for pivotmotion are obscured under the friction blocks 28, but strap 23 islabeled at a visible edge in the view.

Pivoting of a seat in the middle range of rotation is intentionallymeant to be dampened in the invention and two means are provided both ofwhich deploy the tube member 24 as a braking surface.

Friction blocks 28 are provided on the underside of seat plate 1 whichprovide concavity to conform to the radius of the tube member 24 andshould be a material that is semi rigid but with high frictioncharacteristics. In FIG. 4 the friction blocks 28 obscure the strapssuch as 23 in FIG. 5 which retain the tube member to the seat plate. Itis preferred to attach the friction blocks 28 in place with the samescrews which would hold straps such as 23 best seen in FIG. 5

As an alternative to frictional material inherent in a frictional block28 it may be preferred to deploy the block only as an appropriatematerial of mounting matrix for gluing and shaping a thinner frictionallayer which is semi rigid, but flexible enough to conform to the radiuswhich is offered by the friction block. The friction blocks 28 are thelocus of a value judgment which is to apply a chosen amount ofresistance according to the weight bearing pressure riding upon thetubemember 24. In some cases the operative value system may be tominimize resistance and provide a smooth and least friction bearingsurface. In such a case the material provided at the friction blockswould be accordingly chosen. A non weight bearing paradigm for brakingis provided next.

Additional braking is provided by positive mechanism which is joined tothe underside of the seatplate 1 by a guide block 20 and nut block 17. Aconstricting brake band 21 surrounds a portion of the tube member 24.The brake band 21 is anchored to guide block 20 at one end and the otherend of the band is joined to a brake pin 18 which passes through nutblock 17 and which is threaded into the housing of nut wheel 16. The pincarries a square profile 19 as it travels through the matching guideblock 20 so that the pin may not rotate and must travel linearlyaccording to threaded turning of nut wheel 16 as it impinges on the nutblock 17 which retains the brake pin under the seatplate. Appropriateliner material with high friction coefficient may be interposed betweenthe brake band 21 and the cylindrical surface of tube member 24

FIG. 5 shows a rear view of an X frame kneeling chair with the seatplate 1 tilted forward and away from the rearward stops 11. Friction pad28 is shown with a concave contour clamped against tube member 24 inalignment with the anchoring of slip strap 23. The friction pad pressesdownward by the simple force of weight bearing upon seatplate 1. Thekneeling region is shown with kneel plate 2 removed to reveal the pairedstraps 29 and 30 anchoring tube member 25 to the kneeling plate 2 (whichis removed) and to x member 4 respectively. It should be noted that theoutside set of the paired straps, which anchor the plate at 29, areaccessible for mounting outside of the width of x member 4. Bumper stops31 are shown to protect x member 4 from full impingement by a mountedkneel plate and it is preferred that they be higher than the diameter ofa human finger.

In this perspective depiction, further demonstration that the seat plateis not parallel to the surface of frame extension 10 is revealed by thenon parallel relation of the mounting flange portions of each strappair. It should be noted that the slip strap 23 (and its counterpartstrap in the opposite pair of straps which anchor to seat plate 1) aresituated along the length of the tube member 24 outside of the width ofx member 3 so that mounting of the seat to the tube with the strap 23can be easily accomplished after the tubemember 24 is previously fixedto the frame by strap 22 where it resides under the mid region of seatplate 1. This effectively overcomes the previously described problemthat leaf hinges are disadvantageous to deploy in the difficult midregion between two broad surfaces in order to rotate. Even if such leafhinges can function in conjunction with bulky shim blocks to allow arange of rotation, once applied to the first rotational part they mayrequire provision of access holes in that first part in order to attachthe leaf to the second part which is obscured by the first, or the hingeitself would require an offset along axis of the rotation which ispartly outside of the width of the x member 3. Accomplishing pivot withthe axle and strapping is advantageous on sequential assembly.

FIG. 6 shows modification of a C frame kneeling chair in the upperhooked inclined regions 8 of the paired and parallel frame which hasbeen previously been shown in the prior art FIG. 2. Although the profileof a C frame kneeling chair can be made from tubular metal, in generalthe C frame kneeling chair is often appreciated as furniture for beingmolded of bent wood construction, however such continuous layeredmolding cannot provide the cantilevered frame extension 10 for mountingrear stops 11. Similarly the paired C frames of metal tubing are alsoobtained as a series of bends in a continuous length of tubing.

Two fixed plates are bridged between the rails of the C frames at thehooked region 8. Plate 32 serves as a mounting site for an anterior stopsuch as 13 provides in the prior figures for an X frame. The rearwardbridging plate 31 is a cantilevered extension from the C frames withbracing 33 for attachment and analogous to the previously shown frameextension 10 of earlier FIGS. 3, 4, 5 and provides mounting sites forrear stops at 35.

An angle of greater than 180 degrees is formed with the surface offorward bridge plate 32 which provides a forward stop site 34. Thetubular member for defining an axis of rotation would be placed near tothe intersection of either plate for example on rear plate 31 in thelong rectangular region shown as 36. The intersecting angle defined byplate 32 and 31 could be provided in a modified molded profile for the Cframe so that tube 24 could be mounted on the bare frames at theapproximate intersect of the provided angle. It can be appreciated thatthe provision of bridging plates is not necessary for the mounting of atube member with straps to provide rotation of a plate in relation to aframe region. However the provision of the rearward plate 31, analogousto frame extension 10 in the X frame figures, is the preferred extensionof paired C frames for limiting backward tilting of a seat plate.Bumpers or stops to avoid impingement of a rotating plate against framemembers may be applied to those regions of the frame or plate whichimpinge, but it is preferred to provide the bridging plates for themounting of such stops whether the stops are of single or adjustabledimension.

Analogous extension plates could be provided for limits to knee platerotation, though usually the lesser range of rotation of a knee platedoes not require rotation to approximate horizontal orientation. Theincline surface of the hook region 8 in a typical C frame is sufficientto mount a tube member 25 to serve a kneel plate. Bumper stops may beprovided on such a hook region as the lesser degree of rotation providedby the elevation of the axis of rotation is acceptable. Rigidity betweenthe frame members is also not a mandatory reason for providing eithersingle or a pair of extension plates at the kneeling region of the Cframe chair so long as sufficient rigidity is accomplished by dedicatedrigidity plates such as 9 in FIG. 2 of the prior art.

It can be seen that the invention as taught has ready application to theexisting frames of kneeling chairs which deploy only fixed seat andkneeling surfaces. As shown in the specification, tilting for sittingand kneeling plates of a kneeling chair are enabled to rotate in twodirections around an axis of rotation which is provided in the middleregion of each plate. This allows the user to seek out a locus ofbalance that is still central in the plate while the range of rotationvaries away in two directions. In one case the tilting is forward indegrees of increasing inclination where the user eventually chooses toseek the benefit of a vector of added support support by deploying kneesupon a kneeling plate. When a user does deploy one or both knees forsupport, the rotation of a knee plate provides variability for thediffering strike angle of the pretibial below knee leg surface whichvaries according to the leg length of the user.

In the other case the user may tilt backward with less inclinationapproaching horizontal, where the human anatomy does not have any rearward appendages to counter and where rearward stops are provided.Rearward rotation may also be carried to posterior ranges ofinclination, which are beyond horizontal, according to either fixed oradjustable stops mounted on an extension region. Although frameextension 10 in FIGS. 3, 4, 5 is depicted as horizontal it may bepreferred to have additional rearward slope allowing such greaterposterior inclination. Surfaces and hardware are provided for stops inboth directions. It must be appreciated that the deployment ofadjustable stops even in the rearward direction may be desirable andsome users may wish to adjust the degree of rearward tilt to go beyondhorizontal. The adjustable stop as provided forward is deployable bothfrontward and rearward. The appropriate extension of frame or bridgingplates are provided for mounting both rearward and forward limit stopsand for mounting hardware to determine an axis of rotation in the middleregion of a broad plate held relatively closely to a frame structure.

The straight line between forward and rearward limit stops defines a 180degree virtual plane from which the axis of rotation must be elevatedaway to achieve any rotation. A range of rotation is achievable by anygreater displacement of the axis of rotation from the virtual plane bythe placement of an extension plate angled from the frame such that theaxis of rotation falls further outside of the virtual plane formed byforward and rear stops. Additionally the tilt may be tuned for greaterrange of rotation by providing a larger diameter axle or providing shimblocks between for the axle in relation to either the moving plate or tothe frame in order to offset the axis of rotation from the either of thepaired parts which share an rotational reference. In the choice of theinvention shim blocks are provided to offset from the seat plate toprovide a component of offset and rotational range and since that shimblock is deployed between the rotational part (the seat plate) ratherthan the fixed part (the frame) then it serves as a friction block withselected braking by coefficient of friction. The invention providesoffset by frame extension anatomy, by axle diameter, and by chosen shimblocks, all of which may be varied to a goal of rotation range.

The mounting of hardware to accomplish this is convenient tomanufacturing and ready to assemble users and the spatial tolerancesprovide ease of access for monitoring and maintenance of the hardwareparts such as straps. The open spaced elements of the invention providesafety to avoid the hazards of pinch injury.

The tube members provide a number of intended advantages over simplehinges which join either plate to its respective x member 3 or 4. Ifleaf hinges were provided to define a rotational axis, there wouldundoubtedly be two needed for each plate/member site and those twohinges would also be preferred to be mounted far apart along the axis ofrotation for stability. The tubular member provides a single lightweight alternative to multiple hinges or to hinges which might share asolid single pin for stability, such as the so called piano hinge. Inthe invention straps are elected which are widely spaced and which couldbe supplemented to be more than two for each rotating plate or framemember region chosen. Although straps are deployed and convex channelswithin spacer blocks are provided, other analogous mounting hardwarecould include stamped and press formed channels of sheet metal materialequivalent to straps and spacer blocks.

The elements to enable rotation provide shimming which can be sized toaccommodate varied ranges of rotation and provide a long axis ofrotation stabilized at rotational anchors that are far apart andinexpensive as in the case of straps. The tube member provides theoperating surface for matching to a braking material which can be selfaligning during wear. Additional braking elements are provided forpositive mechanical breaking which can be adjustable tension.

A tube member as an axis of rotation provides substantial rigiditybetween two relatively far apart points of strapping so that a tubemember contributes to the stability between outlying members of a frame(as described in the case of the C frame of paired and parallel members)especially as addition strapping pieces or cylindrical tunnels ofstrapping may be applied.

Discussion has conveyed how the range of rotation may mandate differingchoices of diameter for the tubular axle member, but it must be notedthat other mandates may apply to choice of diameter of axle, such as themandate to have a given circumferential dimension for the application ofbraking and also having sufficient diameter in proportion to tubularlength to provide rigidity. Additionally although the inventionadvocates hollow tubing such as metal which is inexpensive and veryrigid, other materials might be chosen for an axle which is low density,highly rigid but solid, including polymers which may be extruded hollowor solid.

In regard to the use of a single axle to define a rotating relationshipbetween joined parts, it must be remembered that such an axle is electedto be fixed (non rotating) to at least one of those parts in order toenable a braking of rotation between those parts. Where braking is not aconcern then the axle may be retained by simple means that allow asimple floating rotation to both of the joined parts (plate and frame).

It must also be appreciated that the invention has employed a brakingstrap which originates and terminates entirely on one joined parts whichis a rotatable seat plate, and the seat is braked against a fixed axlewhich is on a frame member. Analogous braking parts could transposedentirely to mounting upon a frame member while converting the axle to afixed relationship with a seat plate and accordingly still accomplish abraking relationship. In such a case the axle and seat plate wouldrotate within the retaining straps and braking band mounted on theframe. Because the axle provides a stationary virtual axis of rotation,it is even possible to split the mounting of a tensioned braking strapso that the strap originates on the frame, and contacts the axle surfaceto then terminate for tensioning elsewhere upon the seat plate. Suchtransposition or even separation of origination and termination betweenrespective frame and plate are within the teaching of the invention evenwhich has a preferred choice.

The brake band and associated hardware is originated on the seat platefor uniformity of function and manufactured association and for mostconvenient placement of the terminating portion in a tensioning nutwheel.

The principles taught can also be deployed to tiltable seat surfacesinteracting with frame parts on chairs which may not present inclinedframe surfaces and which are not intended for kneeling. In addition tothe specifics demonstrated as preferred in the invention here,principles have been taught which are applicable to the relation of aseat surface or support surface in other items of furniture or fixture.For example an individual may employ the seat plate of the invention astilting with a range of forward and reverse inclination on both sides ofhorizontal and with dampened braking features without ever choosing touse the kneeling elements, in which case the kneeling chair isfunctioning as a balance stool for choosing sitting postures in a rangeof tilt. For such a stool in production, the principles of assembly andthe range of inclination defined by forward and rear stops and theoffset of axis in the tube between those stops has been taught. Othermaterials may be deployed including a variety of joining and anchoringmaterials and hardware which still are derived to maintain the geometricprinciples applied in the embodiments. The embodiment of the inventionin the specification defines principles which are further stated in theclaims

1. I claim in a kneeling chair having an inclined seat plate and a kneeplate, each mounted to a respective frame member the inventioncomprising a tiltable seat provided as a plate, or a tiltable knee restas a plate (or both said plates provided in the same said chair), eachsaid plate joined to each said respective frame member in a hingedrelationship to said frame member.
 2. The invention in claim 1 includingwherein said hinged relationship is accomplished by a reference axle towhich said plate and said frame member are joined and where one or bothof said plate and said frame member are enabled to rotate around saidreference axle and including where said reference axle is tubular. 3.The invention in claim 2 wherein said reference axle is fixed inrelationship only to either said frame member or to said plate(designated as the fixed pair part) and the remaining one of the two(said frame member or said plate) remains a rotatable pair part inrelation to said reference axle.
 4. The invention in claim 2 whereinsaid axle is retained around portions of its circumference within straplike anchors, said straps being fastened to said frame member and tosaid plate which are joined in an operating pair.
 5. The invention inclaim 2 wherein said plate, which may serve as a seat, is provided witha shim block, with cylindrical recess to mate with the circumference ofthe tubular axle at one or more points under said seat plate wherein theweight of said plate is applied through said shim block, and where saidshim block may be chosen for its preferred coefficient of frictionagainst the circumference of said reference axle.
 6. The invention inclaim 5 wherein said shim block provides additional clearance at saidcylindrical recess providing for the insertion and fixation of aselected layer of material offering a chosen coefficient of frictionoperative against said axle surface.
 7. The invention in claim 3 whereinsaid reference axle is partially surrounded within a braking strapmounted upon a region of said kneeling chair which is a rotatable pairpart and said braking strap provides constriction on the circumferenceof said axle to restrain rotation in relation to said fixed axle mountedon said fixed pair part and said rotational pair part may be a seatplate or a knee plate or both on a given kneeling chair.
 8. Theinvention as in claim 7 wherein said braking strap is adjustable forbraking load comprising an anchoring of one end of strap and a nonrotating pin joined to the other end of said strap and said pin ismoveable along its length by threaded travel through a tightening nut 9.The invention in claim 1 wherein said plate having an anterior region ofimpingement superimposed to its paired frame member during rotation andcarries an anterior stop to limit forward rotation and pinch spacedistance, said stop may be applied to said plate or to its paired framemember.
 10. The invention in claim 9 wherein said anterior stop isadjustable in height comprised by a rotatable rod protruding from saidframe member and enabled to rise or fall according to a threadedrelationship with said frame member.
 11. The invention in claim 1wherein said reference frame member so inclined and serving as supportfor said hinged seat plate is provided with a rearward frame extensionof generally horizontal orientation positioned to limit backward tiltingof said plate and said frame extension may carry 1 or more rearwardstops to alter the angle of backward tilt and the rearward pinch spacedistance between said extension and said plate.
 12. The invention inclaim 11 wherein said rearward stops are adjustable as provided for inclaim 10 by mounting upon a rod having threaded relationship to saidframe extension.
 13. The invention in claim 9 wherein said plate isprovided in a region serving as a knee rest and is provided upon a framemember
 14. The invention in claim 2 wherein a range of rotationalmovement is provided for said plate in relation to said frame memberaccording to offset of the virtual axis of said reference axle fromeither said plate or said frame member which are joined by said axle asa pair and where said offset is provided in relation to either part ofthe pair by a shim block interposed between said axle and said part ofthe pair.
 15. The invention in claim 2 wherein a range of rotationalmovement is provided for said plate in relation to said frame memberaccording to offset of the virtual axis of said reference axle from bothsaid plate or said frame member which are joined by said axle as a pairand where said offset distance is provided in relation to both parts ofthe pair by an axle of chosen enlarged diameter interposed between saidaxle and said parts of the pair, including wherein said axle is tubularor otherwise constructed of a low density matrix.